CN114679053B

CN114679053B - Power supply system, control method thereof and electronic equipment

Info

Publication number: CN114679053B
Application number: CN202210397060.6A
Authority: CN
Inventors: 彭博
Original assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Current assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Priority date: 2022-04-15
Filing date: 2022-04-15
Publication date: 2023-05-02
Anticipated expiration: 2042-04-15
Also published as: CN114679053A

Abstract

Provided are a power supply system, a control method thereof, and an electronic device, including: the switching power supply comprises a power supply output end and has various switching frequencies; the capacitors are in one-to-one correspondence with the switching frequencies, and each capacitor in the capacitors is used for filtering noise of the switching frequency corresponding to each capacitor in the switching frequencies; the switch module is positioned between the plurality of capacitors and the power supply output end and is used for responding to the current working frequency of the switch power supply, controlling the first capacitor corresponding to the current switching frequency in the plurality of capacitors to be in a working state, and controlling the other capacitors except the first capacitor in the plurality of capacitors to be in a non-working state. The corresponding capacitors are selected according to the current switching frequency to be connected into the power supply output end so as to filter switching noise corresponding to the current switching frequency, and the problem that the power supply system performance is reduced and even the power supply system is damaged due to overlarge surge current caused by the fact that a plurality of capacitors are connected in parallel with the output end at the same time is avoided.

Description

Power supply system, control method thereof and electronic equipment

Technical Field

The application relates to the technical field of power supplies, in particular to a power supply system, a control method thereof and electronic equipment.

Background

The switching power supply has characteristics of small size, light weight and high efficiency, so that a power supply system using the switching power supply as a core is widely used in various fields. As the switching frequency changes, the frequency of the switching noise of the power supply system also changes. In the related art, a method of connecting a plurality of capacitors in parallel is adopted to filter switching noise with various frequencies.

However, the more capacitances the output terminals are connected in parallel, the larger the equivalent capacitance value. Thus, at the moment of the start-up of the power supply system, the surge current value becomes larger. Excessive surge current values can affect the performance of the power supply system and even damage components inside the power supply system.

Disclosure of Invention

The embodiment of the application provides a power supply system, a control method thereof and electronic equipment.

In a first aspect, there is provided a power supply system comprising: the switching power supply comprises a power supply output end and has various switching frequencies; the capacitors are in one-to-one correspondence with the switching frequencies, and each capacitor in the capacitors is used for filtering noise of the switching frequency corresponding to each capacitor in the switching frequencies; the switch module is positioned between the plurality of capacitors and the power supply output end and is used for responding to the current working frequency of the switch power supply, controlling the first capacitor corresponding to the current switching frequency in the plurality of capacitors to be in a working state, and controlling the other capacitors except the first capacitor in the plurality of capacitors to be in a non-working state.

In a second aspect, there is provided a control method of a power supply system including: the switching power supply comprises a power supply output end and has various switching frequencies; the capacitors are in one-to-one correspondence with the switching frequencies, and each capacitor in the capacitors is used for filtering noise of the switching frequency corresponding to each capacitor in the switching frequencies; the switch module is positioned between the plurality of capacitors and the power supply output end, and the control method comprises the following steps: and controlling a first capacitor corresponding to the current switching frequency in the plurality of capacitors to be in an operating state in response to the current operating frequency of the switching power supply, and controlling other capacitors except the first capacitor in the plurality of capacitors to be in a non-operating state.

In a third aspect, an electronic device is provided, comprising, a load device; the power supply system of the first aspect for supplying power to a load device.

According to the embodiment of the application, the corresponding capacitor is selected according to the current switching frequency to be connected into the power supply output end so as to filter the switching noise corresponding to the current switching frequency, and the problem that the power supply system performance is reduced and even the power supply system is damaged due to the fact that a plurality of capacitors are connected in parallel at the output end simultaneously to cause overlarge surge current is avoided.

Drawings

Fig. 1 is a schematic diagram of a Buck DC/DC switching power supply (Buck).

Fig. 2 is an example diagram of controlling the duty cycle of the output voltage of the switching power supply based on PWM.

Fig. 3 is an example diagram of controlling the duty cycle of the output voltage of the switching power supply based on PFM.

Fig. 4 is a diagram showing an example of filtering switching noise of various frequencies of a switching power supply in the related art.

Fig. 5 is a schematic diagram of the insertion loss of the capacitor C1 in fig. 4.

Fig. 6 is a schematic diagram of a power supply system according to an embodiment of the present application.

FIG. 7 is a schematic diagram of one implementation of a detection module of a power supply system.

FIG. 8 is a schematic diagram of one implementation of a power supply system.

Fig. 9 is a schematic diagram of an electronic device according to an embodiment of the present application.

Fig. 10 is a flowchart of a power system control method according to an embodiment of the present application.

Detailed Description

The following description of the technical solutions in the embodiments of the present application will be made clearly and completely with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are only some embodiments of the present application, not all embodiments.

Switching power supplies are an indispensable power supply mode for rapid development of the electronic information industry at present. The power supply system taking the switching power supply as the core is widely applied to the fields of industrial automation control, military equipment, scientific research equipment, LED illumination, industrial control equipment, communication equipment, power equipment, instruments and meters, medical equipment, semiconductor refrigeration and heating, air purifiers, electronic refrigerators, liquid crystal displays, LED lamps, communication equipment, audiovisual products, security monitoring, LED lamp strips, computer cases, digital products, instruments and the like.

When the switching frequency of the power supply system is changed, the frequency of the switching noise of the power supply system is also changed. In order to effectively filter out switching noise, a method of connecting a plurality of capacitors in parallel is adopted in the related art. However, the more capacitors connected in parallel, the larger the surge current value at the moment of starting the power supply system. Excessive surge current values can affect the performance of the power supply and even damage components inside the power supply system.

For ease of understanding, the above-mentioned problems are illustrated in detail below with reference to fig. 1, taking a power supply system as an example of a step-down DC/DC switching power supply (Buck).

The DC/DC switching power supply maintains a stable output by controlling a time ratio of switching on and off of the switching transistor.

As shown in fig. 1, buck may include an input power source 110, a controller 130,

switching devices

120 and 121, an inductor 140, a capacitor 150, a load 160, and the like.

The switching device 120 is any switching device that can change the on-off state in a controlled manner. For example, the transistor may be a MOSFET or an IGBT. The switching device 121 is any switching device that can be turned on when the switching device 120 is turned off to complete freewheeling, and turned off when the switching device 120 is turned on. For example, the semiconductor device may be a MOSFET, an IGBT, or a diode.

Buck utilizes the energy storage function of the inductor 140 to realize voltage reduction output by controlling the on and off of the

switching devices

120 and 121. Output voltage V _o And input voltage V _in The relation of (2) is:

V _o ＝V _in ×d

where d is the duty cycle of the switching device 120, i.e., the ratio of the time the switch is open to the period in one cycle.

As can be seen from the above formula, the control of the output is actually achieved by the control of the duty cycle. The method of controlling the duty ratio d by the controller 130 may be Pulse Width Modulation (PWM) or Pulse Frequency Modulation (PFM).

PWM is a control method in which the period is constant, and the change of the duty ratio d is achieved by controlling the time (ON) at which the switch is turned ON in each period. Fig. 2 is an example diagram of controlling the duty cycle of the output voltage of the switching power supply based on PWM. The pulses in fig. 2 may be used to drive switching device 120 in fig. 1. As shown in fig. 2, the switching device 120 is turned on for a time T1 in the first switching period, and the switching period is T, and the duty ratio is d1. The switching period T is kept unchanged, and the on time of the switching device 120 is adjusted to T2 (T2 > T1) in the second switching period, and the duty ratio is d2 (d 2> d 1). The increase in duty cycle is achieved by varying the time that switching device 120 is on during the same period.

PFM is a control method of periodic variation, and is classified into two types, a fixed ON time type and a fixed OFF time type. Taking a fixed ON time type as an example, the time (ON) of opening the switch in each period is unchanged, and PFM is realized by controlling the off time to change the duty ratio d. In other words, the fixed ON time type is that the time (ON) at which the switch is turned ON in each period is unchanged, and PFM is changed by controlling the period change to realize the change of the duty ratio d. Fig. 3 is an example diagram of controlling the duty cycle of the output voltage of the switching power supply based on PFM. The pulses in the figure may be used to drive the switching device 120 in fig. 1.

As shown in fig. 3, the switching device 120 is turned on for a time t in each cycle. The switching device 120 is turned off for a time T3 in the first switching period T1, and the duty ratio is d3. The switching device 120 is turned off for a time T4 during the second switching period T2, and the duty cycle is d4. The switching device 120 is turned off for a time T5 in the third switching period T3, and the duty ratio is d5. The calculation method of the combined duty ratio can show that the fixed ON time type PFM control mode changes the duty ratio by changing the period under the condition that the ON time is unchanged, thereby realizing the change of the power supply output.

Since the switching device operates in a high frequency on-off state, the current flowing through the switching device may vary sharply, thereby generating parasitic components in the loop. Noise interference occurs at the output of the switching power supply under the influence of the loop parasitic component. The noise is mainly provided by switching noise generated by the switching frequency. Switching noise is undesirable and can cause instability of the output voltage, affecting the output performance of the power supply and thus the performance of the load. For example, when the load is a power amplifier in a radio frequency path, switching noise can affect radio frequency performance, such as output radio frequency spectrum characteristics (Output RF Spectrum, ORFS) performance of global system for mobile communications (Global System for Mobile Communications, GSM), and the like.

A capacitor is used in the related art to filter out switching noise. In a switching power supply based on PWM mode, since the period T is constant, that is to say the switching frequency is constant, becauseThe frequency f of the switching noise _pwm Is contemplated. For example, a filter with frequency f can be connected in parallel with the power output end _pwm Is a capacitor of (a). In the PFM mode-based switching power supply, when a load becomes large, a switching period becomes small and a switching frequency becomes high; when the load becomes smaller, the switching period becomes larger and the switching frequency becomes lower. Switching frequency f of PFM-mode-based switching power supply _pfm Is varied. For example, a plurality of capacitors may be reserved between the power supply output and the load input to filter out switching noise at different frequencies. Taking the power supply system shown in fig. 4 as an example, three capacitors C1, C2 and C3 are reserved between the output end of the switching power supply and the input end of the load, so as to filter noise with three frequencies.

The capacitance value has a mapping relation with the frequency of noise which can be filtered. The capacitance does not meet the ideal capacitance characteristics due to parasitic parameters (structure, leads, wiring, etc.). In practical application, the capacitor can be equivalently a circuit of equivalent resistance, equivalent inductance and capacitor in series. The resonant frequency of the equivalent circuit is the Self-resonant frequency (Self-Resonant Frequency, SRF) of the capacitor. SRF is the point where the impedance of the capacitor is the smallest, so the capacitor can effectively filter out noise at the self-resonant frequency point.

Still taking the power supply system of fig. 4 as an example, the insertion loss of the capacitor C1 in fig. 4 is shown in fig. 5. The insertion loss of the capacitor C1 is the frequency domain response of the signal input to the capacitor C1. The frequency corresponding to the lowest point of the curve is the self-resonant frequency of the capacitor C1. The frequency domain response reflects the degree of attenuation of the signal input to capacitor C1. As can be seen from the figure, the insertion loss of the capacitor C1 at the self-resonance frequency point is minimum, that is, the capacitor C1 can effectively filter out noise at the self-resonance frequency point.

However, if the output terminal of the switching power supply has a parallel capacitor, the voltage across the capacitor will rise rapidly at the moment of power supply start, so the capacitor charging current increases sharply. The calculation formula of the charging current is shown below.

I＝C×△U/△t

As can be seen from the above formula, the larger the capacitance value is, the larger the charging current is, and thus the larger the surge current value caused by the charging current is.

The switching power supply based on the PWM mode does not generate excessive surge current because the output end has only one capacitor. And the output end of the switching power supply based on the PFM mode is provided with a plurality of capacitors. According to the characteristic that the capacitance values will be superimposed when the capacitors are connected in parallel, the equivalent capacitance value c=c1+c2+c3 at the output end of the power supply system shown in fig. 4. Therefore, a large surge current is generated at the moment of starting the switching power supply. The surge current can cause damage to components such as a switching device and the like in the switching power supply, so that the switching power supply cannot work. Therefore, too much capacitance cannot be placed between the power supply output and the load input, and thus various switching noises of the PFM-mode-based switching power supply cannot be effectively filtered.

In order to solve the above problems, embodiments of the present application provide a power supply system, a control method thereof, and an electronic device, where a corresponding capacitor is selected according to a current switching frequency to be connected to an output end of a power supply to filter switching noise corresponding to the current switching frequency, so as to avoid the problem that a plurality of capacitors are simultaneously connected in parallel to the output end to cause excessive surge current, thereby reducing performance of the power supply system and even damaging the power supply system.

Fig. 6 is a schematic structural diagram of a power supply system according to an embodiment of the present application. The power supply system 600 shown in fig. 6 may be a power supply device having an AC/DC or DC/DC switching power supply as a main topology.

Referring to fig. 6, a power supply system 600 provided in an embodiment of the present application includes a switching power supply 610, a switching module 620, and a plurality of capacitors 630. The function and implementation of the various components of power supply system 600 are described in detail below in conjunction with fig. 6.

The switching power supply 610 may be used to power a load device. The switching power supply 610 may be an AC/DC switching power supply or a DC/DC switching power supply. For example, the switching power supply 610 may be a Buck, boost, or Buck-Boost, and may also be a forward converter, a flyback converter, or the like.

The switching power supply 610 includes a power output terminal V _o . A plurality of capacitors 630 are connected to the power supply output through the switching module 620. The plurality of capacitors 630 are used to filter out a variety of switching noise. Due to openingThe off noise is generated by the switching device of the system, so that a certain mapping relation exists between the frequency of the switching noise and the switching frequency of the switching device. Based on this mapping relationship, the plurality of capacitors 630 are respectively in one-to-one correspondence with the plurality of switching frequencies. Each of the plurality of capacitors 630 is configured to filter noise at a switching frequency corresponding thereto. For example, the plurality of capacitors 630 includes capacitor 1 and capacitor 2. Capacitance 1 corresponds to switching frequency 1 and capacitance 2 corresponds to switching frequency 2. The capacitor 1 is used for filtering switching noise when the system works at the switching frequency 1; the capacitor 2 is used to filter out switching noise when the system is operating at the switching frequency 2.

The number of the plurality of capacitors 630 may be designed according to the kind of the operation frequency of the system. For example, when the main operation frequency of the system includes 3 kinds, the number of the plurality of capacitors 630 may be set to 3.

There are a number of ways to select each of the plurality of capacitors 630. For example, the plurality of capacitors 630 may be selected to have a self-resonant frequency that is the same as the frequency of the switching noise. Referring again to fig. 5, the frequency at the dashed line is 4500MHz. As an example, the self-resonant frequency point of the capacitor is 4250MHz, and the plurality of capacitors 630 may be selected to filter out switching noise at a frequency of 4250 MHz. As another example, the plurality of capacitors 630 may be selected from capacitors whose frequency difference between the self-resonant frequency and the switching noise satisfies a preset requirement. As an example, the plurality of capacitors 630 may be selected to filter out switching noise at frequencies in the range of 4250MHz ±1%. As another example, the plurality of capacitors 630 may be selected to filter out switching noise in the range of insertion loss less than-30 dB.

The switching module 620 is located between the plurality of capacitors 630 and the power supply output. The switching module 620 is configured to control a first capacitor of the plurality of capacitors corresponding to a current switching frequency to be in an operating state and other capacitors of the plurality of capacitors except the first capacitor to be in a non-operating state in response to the current operating frequency of the switching power supply. The first capacitor of the plurality of capacitors 630 is not specifically defined, but the capacitor corresponding to the current switching frequency is the first capacitor. The first capacitance may be any one of the plurality of capacitances 630, and the first capacitance may be changed as the switching frequency is changed. That is, when the switch module 620 receives the information of the current operating frequency, the capacitor corresponding to the information in the plurality of capacitors 630 may be controlled to be connected to the power output terminal, and the other capacitors in the plurality of capacitors 630 may be controlled to be disconnected from the power output terminal.

The switch module 620 performs control of the on-off states of the plurality of capacitors 630, and may be implemented by a hardware circuit or may be implemented in combination with hardware circuits and software.

The power system can filter out switching noise at different frequencies through the cooperation of the switching module 620 and the plurality of capacitors 630. Meanwhile, at each switching frequency, not all capacitors are in operation. Therefore, the power supply system provided by the embodiment of the application can effectively reduce surge current.

In some embodiments, the power supply system may further include a detection module configured to acquire a current switching frequency, determine the first capacitance, and send a trigger signal carrying the information to the switching module. FIG. 7 is a schematic diagram of one implementation of a detection module.

Referring to fig. 7, a power supply system 700 includes a switching power supply 710, a switching module 720, a plurality of capacitors 730, and a detection module 740. Wherein the switching power supply 710, the switching module 720, and the plurality of capacitors 730 are similar to the modules of fig. 6, they are not described herein.

One end of the detection module 740 is connected to the switching power supply 710, and the other end is connected to the switching module 720. The detection module 740 is configured to send a corresponding trigger signal according to the detected current switching frequency of the switching power supply 710. As an implementation manner, the detection module 740 may be composed of a control module 741 and a storage module 742.

Wherein, the control module 741 is used for controlling the switching frequency of the switching power supply 710. When the load demand changes or a disturbance occurs at the power supply output, the control module 741 may adjust the switching frequency of the switching power supply 710 according to the demand. For example, the control module 741 may control the switching frequency to be increased when the load becomes large. As another example, the control module 741 may control the switching frequency to decrease as the load becomes smaller. As one implementation, the control module 741 may adjust the switching frequency of the switching power supply 710 by altering the count of pulse periods.

There is a mapping relationship between the various switching frequencies and the on-off states of the plurality of capacitors. The mapping relationship may be stored in the storage module 742 in different ways. For example, the mapping information may be stored in a program language such as a case sentence, or may be stored in a table format.

The storage module 742 may determine the first capacitance from the stored mapping information whenever a change in the switching frequency is detected. And simultaneously, a corresponding trigger signal is generated and sent to the switch module 720, so that the switch module 720 is triggered to control the first capacitor to be in a working state.

The power system shown in fig. 8 includes a switching power supply 810, a plurality of capacitors 830, a switching module 820, and a detection module 840. The operation of one possible implementation of the present application is described in detail below with reference to fig. 8.

Referring to fig. 8, the plurality of capacitors 830 includes C ₁ To C _n The detection module 840 includes a control module 841 and a storage module 842. The power supply system is used to power the load 850.

After the power system is started, the switching power supply 810 sets a switching frequency of the switching power supply 810 through the control module 841 according to the power consumption requirement of the load 850. The switching power supply 810 adopts a PFM control mode.

The control module 841 sets the switching frequency and simultaneously transmits current switching frequency information to the storage module 842. The memory module 842 queries mapping information between the plurality of switching frequencies and the plurality of capacitors 830 stored therein, determines the operating capacitance among the plurality of capacitors 830, and sends the information to the switching circuit 820.

The switch circuit 820 sets the on-off states of the plurality of capacitors 830 according to the information sent by the memory module 842.

For example, the control module 841 sets the current operating frequency to f according to the load requirement ₁ And simultaneously sends the frequency information to the memory module 842. The memory module 842 can obtain, according to the mapping relationship between the internal stored switching frequencies and the capacitors 830: capacitor C ₁ Can filter out the switching frequency f ₁ And switching noise at the output end of the power supply. While the memory module 842 sends the query result to the switching circuit 820. After receiving the trigger message, the switch circuit 820 turns on the IN terminal and the OUT1 terminal, and the OUT2 to OUTn terminals are all turned off from the IN terminal.

As another example, when the load demand changes, the control module 841 adjusts the current operating frequency to f ₂ And simultaneously sends the frequency information to the memory module 842. The memory module 842 can obtain, according to the mapping relationship between the internal stored switching frequencies and the capacitors 830: capacitor C ₂ Can filter out the switching frequency f ₂ And switching noise at the output end of the power supply. While the memory module 842 sends the query result to the switching circuit 820. After receiving the trigger message, the switch circuit 820 disconnects the IN terminal from the OUT1 terminal, and simultaneously connects the IN terminal to the OUT2 terminal, and the other capacitive paths remain disconnected.

Therefore, only one capacitor is connected to the power supply path regardless of the change in the switching frequency. Thus, noise corresponding to the current switching frequency can be filtered, and surge current can be effectively reduced.

It should be noted that the above is only one possible division manner of the power supply system. The method can be flexibly divided according to the requirements in practical application. For example, the switching module and the plurality of capacitors may be integrated in the switching power supply, the switching module and the plurality of capacitors may be integrated in the load, or may be independent modules.

Referring to fig. 9, the embodiment of the application further provides an electronic device. The electronic device 900 includes a power supply system 910 and a load device 920.

The power supply system 910 may be a power supply system as described in any of the foregoing implementations. The power supply system is used to power the load device 920.

The apparatus embodiments of the present application are described above in detail in connection with fig. 5 to 9, and the method embodiments of the present application are described below in detail in connection with fig. 10. It is to be understood that the description of the method embodiments corresponds to the description of the device embodiments, and that parts not described in detail can therefore be seen in the preceding device embodiments.

Fig. 10 is a flowchart of a control method of a power supply system according to an embodiment of the present application.

The control method 1000 is used to control a power supply system. The power supply system includes: the switching power supply comprises a power supply output end and has various switching frequencies; the capacitors are in one-to-one correspondence with the switching frequencies, and each capacitor in the capacitors is used for filtering noise of the switching frequency corresponding to each capacitor in the switching frequencies; and the switch module is positioned between the plurality of capacitors and the power supply output end.

The control method 1000 of the power supply system includes steps S1010 and S1020, in which:

s1010, detecting the current working frequency of the switching power supply;

s1020, controlling a first capacitor corresponding to the current switching frequency in the plurality of capacitors to be in an operating state, and controlling other capacitors except the first capacitor in the plurality of capacitors to be in a non-operating state.

Optionally, the control method further includes: and detecting the switching frequency of the switching power supply by using the detection module, and sending a trigger signal to the switching module to trigger the switching module to control the first capacitor to be in a working state in response to detecting that the switching frequency of the switching power supply is switched to the current switching frequency.

Optionally, the detection module includes: the control module is used for controlling the switching frequency of the switching power supply; and the storage module is used for storing the mapping relation of the on-off states between various switching frequencies and various capacitors of the switching power supply.

Optionally, the control method includes: the switching power supply is a PFM mode-based switching power supply.

In the above embodiments, it may be implemented in whole or in part by software, hardware, firmware, or any other combination. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the processes or functions in accordance with embodiments of the present application are produced in whole or in part. The computer may be a general purpose computer, a special purpose computer, a computer network, or other programmable apparatus. The computer instructions may be stored in or transmitted from one computer-readable storage medium to another, for example, by wired (e.g., coaxial cable, fiber optic, digital subscriber line (Digital Subscriber Line, DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means from one website, computer, server, or data center. Computer readable storage media can be any available media that can be accessed by a computer or data storage devices, such as servers, data centers, etc., that contain an integration of one or more available media. The usable medium may be a magnetic medium (e.g., a floppy Disk, a hard Disk, a magnetic tape), an optical medium (e.g., a digital video disc (Digital Video Disc, DVD)), or a semiconductor medium (e.g., a Solid State Disk (SSD)), or the like.

Those of ordinary skill in the art will appreciate that the elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

In the several embodiments provided in this application, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of elements is merely a logical functional division, and there may be additional divisions of actual implementation, e.g., multiple elements or components may be combined or integrated into another system, or some features may be omitted, or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.

The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed over a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit.

The foregoing is merely specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily think about changes or substitutions within the technical scope of the present application, and the changes or substitutions are intended to be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A power supply system, comprising:

the switching power supply comprises a power supply output end, and the switching power supply has various switching frequencies;

the capacitors are in one-to-one correspondence with the switching frequencies, and each capacitor in the capacitors is used for filtering noise of the switching frequency corresponding to each capacitor in the switching frequencies;

the switch module is positioned between the plurality of capacitors and the power supply output end and is used for responding to the current switching frequency of the switch power supply, controlling a first capacitor corresponding to the current switching frequency in the plurality of capacitors to be in a working state, and controlling other capacitors except the first capacitor in the plurality of capacitors to be in a non-working state.

2. The power supply system of claim 1, further comprising:

the detection module is used for detecting the switching frequency of the switching power supply, and sending a trigger signal to the switching module to trigger the switching module to control the first capacitor to be in a working state in response to detecting that the switching frequency of the switching power supply is switched to the current switching frequency.

3. The power system of claim 2, wherein the detection module comprises:

the control module is used for controlling the switching frequency of the switching power supply;

the storage module is used for storing the mapping relation of the on-off states of the plurality of switching frequencies and the plurality of capacitors of the switching power supply, responding to the switching frequency of the control module to be switched to the current switching frequency, and sending the trigger signal to the switching module.

4. The power supply system of claim 1, wherein the switching power supply is a PFM mode based switching power supply.

5. A control method of a power supply system, characterized in that the power supply system comprises:

a switch module positioned between the plurality of capacitors and the power supply output terminal,

the control method comprises the following steps:

and controlling a first capacitor corresponding to the current switching frequency in the plurality of capacitors to be in an operating state in response to the current switching frequency of the switching power supply, and controlling other capacitors except the first capacitor in the plurality of capacitors to be in a non-operating state.

6. The control method of a power supply system according to claim 5, characterized in that the control method further comprises:

and detecting the switching frequency of the switching power supply by using a detection module, and sending a trigger signal to the switching module to trigger the switching module to control the first capacitor to be in a working state in response to detecting that the switching frequency of the switching power supply is switched to the current switching frequency.

7. The method according to claim 6, wherein the detection module includes:

and the storage module is used for storing the mapping relation of the on-off states of the plurality of switching frequencies and the plurality of capacitors of the switching power supply.

8. The method according to claim 5, wherein the switching power supply is a PFM mode-based switching power supply.

9. An electronic device, comprising:

a load device;

a power supply system according to claims 1-4 for powering said load device.